Prostaglandin e2 receptors in abdominal aortic aneurysm and human aortic smooth muscle cells

AbstractBackgroundProstaglandin (PG) E2 (PGE2) appears to have a role in stimulating production of interleukin-6 (IL-6) and apoptosis of smooth muscle cells in diseased aortic tissue. These actions are mediated by cellular receptors for PGE2 EP receptors.ObjectiveThis study was undertaken to identify EP receptors associated with production of IL-6 by aortic explants.MethodsBiopsy specimens of abdominal aortic aneurysm were used for explant culture and preparation of messenger RNA. The presence of EP1, EP2, EP3, and EP4 receptors in tissue and cells was investigated with reverse-transcriptase polymerase chain reaction. IL-6 and cyclic adenosine monophosphate were measured with an enzyme-linked immunosorbent assay.ResultsPGE2 or 11-deoxy-PGE1 (EP 2/3/4 agonist) reversed partially the indomethacin suppression of IL-6 secretion from explant cultures, whereas butaprost (EP2 receptor agonist) and sulprostone (EP 1/3 receptor agonist) had no effect. Aortic biopsy specimens expressed EP2, EP3-III, and EP4 receptors. Aortic smooth muscle cells expressed EP2 receptor and four variants of EP3 receptor, ie, EP3-Ib, EP3-II, EP3-III, and EP3-IV, but PGE2 did not stimulate secretion of IL-6. In contrast, PGE2 or 11-deoxy-PGE1 stimulated secretion of IL-6 from aortic macrophages.ConclusionsIn aortic explants, PGE2 stimulates IL-6 secretion by activation of EP4 receptors, present in macrophages

A Trans-Atlantic Perspective on Stagnation in Clinical Translation of Antimicrobial Strategies for the Control of Biomaterial-Implant-Associated Infection

Current regulatory requirements impede clinical translation and market introduction of many new antimicrobial combination implants and devices, causing unnecessary patient suffering, doctor frustration, and costs to healthcare payers. Regulatory requirements of antimicrobial combination implants and devices should be thoroughly revisited and their approval allowed based on enrichment of benefit demonstrations from high-risk patient groups and populations or device components to facilitate their clinical translation. Biomaterial implant and devices equipped with antimicrobial strategies and approved based on enrichment claims should be mandatorily enrolled in global registry studies supervised by regulatory agencies for a minimum five-year period or until statistically validated evidence for noninferiority or superiority of claims is demonstrated. With these recommendations, this trans-Atlantic consortium of academicians and clinicians takes its responsibility to actively seek to relieve the factors that stagnate downward clinical translation and availability of antimicrobial combination implants and devices. Improved dialogue between the various key players involved in the current translational blockade, which include patients, academicians and doctors, policymakers, regulatory agencies, manufacturers, and healthcare payers, is urgently needed.</p

Control of Propionibacterium acnes by natural antimicrobial substances: Role of the bacteriocin AS-48 and lysozyme

We report the high susceptibility of several clinical isolates of Propionibacterium acnes from different sources (skin, bone, wound exudates, abscess or blood contamination) to the head-to-tail cyclized bacteriocin AS-48. This peptide is a feasible candidate for further pharmacological development against this bacterium, due to its physicochemical and biological characteristics, even when it is growing in a biofilm. Thus, the treatment of pre-formed biofilms with AS-48 resulted in a dose- and time-dependent disruption of the biofilm architecture beside the decrease of bacterial viability. Furthermore, we demonstrated the potential of lysozyme to bolster the inhibitory activity of AS-48 against P. acnes, rendering high reductions in the MIC values, even in matrix-growing cultures, according to the results obtained using a range of microscopy and bioassay techniques. The improvement of the activity of AS-48 through its co-formulation with lysozyme may be considered an alternative in the control of P. acnes, especially after proving the absence of cytotoxicity demonstrated by these natural compounds on relevant human skin cell lines. In summary, this study supports that compositions comprising the bacteriocin AS-48 plus lysozyme must be considered as promising candidates for topical applications with medical and pharmaceutical purposes against dermatological diseases such as acne vulgaris.This research was funded by a grant from the Spanish Ministry of Economy and Competitiveness (SAF2013-48971-C2-1-R that included funds from European Regional Development, ERDF), and the Research Group General (BIO160, UGR)

Proteome-Wide Analysis of Single-Nucleotide Variations in the N-Glycosylation Sequon of Human Genes

N-linked glycosylation is one of the most frequent post-translational modifications of proteins with a profound impact on their biological function. Besides other functions, N-linked glycosylation assists in protein folding, determines protein orientation at the cell surface, or protects proteins from proteases. The N-linked glycans attach to asparagines in the sequence context Asn-X-Ser/Thr, where X is any amino acid except proline. Any variation (e.g. non-synonymous single nucleotide polymorphism or mutation) that abolishes the N-glycosylation sequence motif will lead to the loss of a glycosylation site. On the other hand, variations causing a substitution that creates a new N-glycosylation sequence motif can result in the gain of glycosylation. Although the general importance of glycosylation is well known and acknowledged, the effect of variation on the actual glycoproteome of an organism is still mostly unknown. In this study, we focus on a comprehensive analysis of non-synonymous single nucleotide variations (nsSNV) that lead to either loss or gain of the N-glycosylation motif. We find that 1091 proteins have modified N-glycosylation sequons due to nsSNVs in the genome. Based on analysis of proteins that have a solved 3D structure at the site of variation, we find that 48% of the variations that lead to changes in glycosylation sites occur at the loop and bend regions of the proteins. Pathway and function enrichment analysis show that a significant number of proteins that gained or lost the glycosylation motif are involved in kinase activity, immune response, and blood coagulation. A structure-function analysis of a blood coagulation protein, antithrombin III and a protease, cathepsin D, showcases how a comprehensive study followed by structural analysis can help better understand the functional impact of the nsSNVs

Combinatorial discovery of polymers resistant to bacterial attachment

Bacterial attachment and subsequent biofilm formation are key challenges to the long term performance of many medical devices. Here, a high throughput approach coupled with the analysis of surface structure-property relationships using a chemometics approach has been developed to simultaneously investigate the interaction of bacteria with hundreds of polymeric materials on a microarray format. Using this system, a new group of materials comprising ester and hydrophobic moieties are identified that dramatically reduce the attachment of clinically relevant, pathogenic bacteria (Pseudomonas aeruginosa, Staphylococcus aureus and uropathogenic Escherichia coli). Hit materials coated on silicone catheters resulted in up to a 30 fold reduction in coverage compared to a commercial silver embedded catheter, which has been proven to half the incidence of clinically acquired infection. These polymers represent a new class of materials resistant to bacterial attachment that could not have been predicted from the current understanding of bacteria-surface interactions

Damaged Intestinal Epithelial Integrity Linked to Microbial Translocation in Pathogenic Simian Immunodeficiency Virus Infections

The chronic phase of HIV infection is marked by pathological activation of the immune system, the extent of which better predicts disease progression than either plasma viral load or CD4+ T cell count. Recently, translocation of microbial products from the gastrointestinal tract has been proposed as an underlying cause of this immune activation, based on indirect evidence including the detection of microbial products and specific immune responses in the plasma of chronically HIV-infected humans or SIV-infected Asian macaques. We analyzed tissues from SIV-infected rhesus macaques (RMs) to provide direct in situ evidence for translocation of microbial constituents from the lumen of the intestine into the lamina propria and to draining and peripheral lymph nodes and liver, accompanied by local immune responses in affected tissues. In chronically SIV-infected RMs this translocation is associated with breakdown of the integrity of the epithelial barrier of the gastrointestinal (GI) tract and apparent inability of lamina propria macrophages to effectively phagocytose translocated microbial constituents. By contrast, in the chronic phase of SIV infection in sooty mangabeys, we found no evidence of epithelial barrier breakdown, no increased microbial translocation and no pathological immune activation. Because immune activation is characteristic of the chronic phase of progressive HIV/SIV infections, these findings suggest that increased microbial translocation from the GI tract, in excess of capacity to clear the translocated microbial constituents, helps drive pathological immune activation. Novel therapeutic approaches to inhibit microbial translocation and/or attenuate chronic immune activation in HIV-infected individuals may complement treatments aimed at direct suppression of viral replication

Need for recovery amongst emergency physicians in the UK and Ireland: A cross-sectional survey

OBJECTIVES: To determine the need for recovery (NFR) among emergency physicians and to identify demographic and occupational characteristics associated with higher NFR scores. DESIGN: Cross-sectional electronic survey. SETTING: Emergency departments (EDs) (n=112) in the UK and Ireland. PARTICIPANTS: Emergency physicians, defined as any registered physician working principally within the ED, responding between June and July 2019. MAIN OUTCOME MEASURE: NFR Scale, an 11-item self-administered questionnaire that assesses how work demands affect intershift recovery. RESULTS: The median NFR Score for all 4247 eligible, consented participants with a valid NFR Score was 70.0 (95% CI: 65.5 to 74.5), with an IQR of 45.5-90.0. A linear regression model indicated statistically significant associations between gender, health conditions, type of ED, clinical grade, access to annual and study leave, and time spent working out-of-hours. Groups including male physicians, consultants, general practitioners (GPs) within the ED, those working in paediatric EDs and those with no long-term health condition or disability had a lower NFR Score. After adjusting for these characteristics, the NFR Score increased by 3.7 (95% CI: 0.3 to 7.1) and 6.43 (95% CI: 2.0 to 10.8) for those with difficulty accessing annual and study leave, respectively. Increased percentage of out-of-hours work increased NFR Score almost linearly: 26%-50% out-of-hours work=5.7 (95% CI: 3.1 to 8.4); 51%-75% out-of-hours work=10.3 (95% CI: 7.6 to 13.0); 76%-100% out-of-hours work=14.5 (95% CI: 11.0 to 17.9). CONCLUSION: Higher NFR scores were observed among emergency physicians than reported in any other profession or population to date. While out-of-hours working is unavoidable, the linear relationship observed suggests that any reduction may result in NFR improvement. Evidence-based strategies to improve well-being such as proportional out-of-hours working and improved access to annual and study leave should be carefully considered and implemented where feasible